Weld rod containing manganese

ABSTRACT

A cored wire welding electrode for welding cast iron having an outer sheath made of nickel or a nickel-iron alloy and a powedered core composition containing copresent metallic magnesium and graphite and slag-forming ingredients along with special amounts of manganese. The electrode is particularly useful for open arc welding wherein a high strength weld deposit is required.

United States Patent "1191 Bishel I 1*N0v. 26, 1974 WELD ROD CONTAINING MANGANESE [56] References Cited [75] Inventor: Robert A. Bishel, Huntington, W. UNITED S S TENTS Va. 2,761,796 9/1956 Wasserman 148/26 X 3,235,405 2/1966 Q I48 24 X [73] Assigneez The International Nickel Company, 3309490 3/1967 r f I I I n 219 46 x Inc-1 New YOYk 3,345,495 10/1967 01111115 et al. 219/146 1 Notice: The portion ofthe termofthis 3,554,791 1/1971 Johnson et al. [48/24 ux patent subsequent to Dec. 1 l, 1990, has been disclaime Primary Exammer.l. V. Truhe [22] F] d D 10 1973 Assistant ExaminerN. D. Herkamp 1e ec.

[21] Appl. No.: 423,291 ABSTRACT A cored wire welding electrode for welding cast iron w? Apphcamm Data having an outer sheath made of nickel or a nickel-iron [63] g g lggg g 2391531 March alloy and a powedered core composition containing 1972 copresent metallic magnesium and graphite and slagforming ingredients along with special amounts of 2% 219/146 2 1 22 3; manganese. The electrode is particularly useful for g i 148/24 open arc welding wherein a high strength weld deposit is required.

2 Claims, No Drawings WELD ROD CONTAINING MANGANESE The present applicationis a continuation-in-part of U.S. application Ser. No. 239,531 filed on Mar. 29, 1972 now U.S. Pat. No. 3,778,588.

in U.S. application Ser. No. 239,351 applicant disclosed certain improvements related to weld rods suitable for high rate arc welding of cast iron by automatic coil fed welding machines. In his prior application, applicant discloses a cored-wire welding electrode adapted to weld gray cast iron or ductile cast iron comprising a tube of an alloy containing about 45% to about 100% nickel with the balance, if any, being essentially iron, the tube comprising about 75% by weight of the total electrode and enclosing core composition which comprises the balance of the electrode. The core composition contains, in per cent by weight of core composition, a mixture of line powders comprising about 0.7% to about 3.5% magnesium advantageously alloyed in a concentration of less than about 70% (as, for example, in the form of about 5% to about nickel-magnesium alloy containing about 14% to 17% magnesium and/or in the form of a magnesiumaluminum alloy containing about 65% magnesium) about 5% to about graphite up to about 10% aluminum, up to about 3% alloyed calcium metal, up to 7% metallic silicon, both calcium and silicon being present, for example, in the form of up to about 7% calcium-silicon alloy with the calcium being about to 33% of the alloy or with silicon being present in the form of up to about 20% of an alloy containing about 60% nickel, 30% silicon and about 10% iron, up to about 15% electrolytic manganese (or up to about 35% ferromanganese), about 30% to about or even 75% calcium fluoride, up to 15% cryolite, up to about 6% periclase, i.e., magnesium oxide, and up to about 4% barium fluoride. The core can also contain up to about 5% titanium as titanium metal or nickel-titanium or ferro-titanium alloy, up to about 25% iron, up to about 36% nickel, the iron and the nickel ranges being inclusive of iron and nickel alloyed with magnesium, silicon, manganese, titanium and the like, up to about 5% barium carbonate, up to 5% strontium carbonate, up to about 25% calcium carbonate, up to 10% manganese dioxide and up to about 4% zirconium oxide. The core compositions used in the electrode of the present invention can also include as slag-forming substances up to about 20% calcined alumina, up to about 10% calcium silicate, up to about 10% hematite (ferric oxide), up to about 5% lithium carbonate, up to about 5% lithium fluoride, up to about 20% nepheline syanite, up to about 5% potassium zirconium fluoride, up to about 10% titanium dioxide and up to about 10% sodium fluoride. Other metallics which can be incorporated into the core composition include up to about 6% columbium, as, for example, up to about 10% ferrocolumbium, up to about 4% molybdenum as, for example, up to about 5% ferromolybdenum, up to about 6% of rare earth silicide and up to about 10% tungsten. Generally speaking, the ratio of nickel to metallic iron in the electrode is at least about 0.67.

Further, applicant discloses in his parent U.S. application Ser. No. 239,531 that advantageous weld rods can include ingredients, in per cent by weight of the total weight of the core and the tubular sheath as set forth in Table l.

TABLE I Specific Example Advantagcous Range Ingredient '7! by weight 7! by weight Carbon (as graphite) 3.60 1.5 7.5 Manganese 1.55 up to 7.5 lron 33.70 9 42 Nickel 42.80 29.3 76 Nickel & Iron 85 Silicon (metallic) 0.875 up to 2.5 Copper 0035 up to 0.7 Aluminum 0030 up to 2 Calcium (metallic) 0.38 up to 1 Magnesium (metallic) 0.42 0.25 1.0 Ca 13.10 8 l8- Na AlF 2.25 0 3 BaF 0.75 0 1.5 MgO 0.51 0.25 1.5

In his parent application, applicant also discloses that while it has been stated hereinbefore that the tube portion of the welding electrode of the present invention comprises about by weight of the electrode with the core being the balance, those skilled in the art will appreciate that some modification of this ratio is possible. For example, if the core composition is modified to include iron and nickel in the maximum amounts as set forth hereinbefore, the weight of the tubular sheath can be as low as about 55% by weight of the total electrode. Thus, it is within the contemplation of a more advantageous aspect of the present invention that the tube can comprise about 55% to about by weight of the welding electrode provided that the total per cent of nickel plus iron in the electrode is about 65% to about and the ratio of the nickel to iron is about 0.82 to about 1.6. It is generally advantageous to maintain the tubular sheath at about 65% to 80% by weight of the electrode with the core being about 20% to 35% by weight of the electrode and to form the sheath from an alloy containing a maximum of about 75% nickel.

While the parent application was concerned principally with a weld wire used with an open are, it was disclosed that the wire of that invention could be used with gas shielding or with excess slag in the submerged are process. Examples of welding under submerged are conditions were anomalous in two respects. Firstly, the strength of the submerged arc weld deposits was higher than the strength of deposits made using open arc techniques. Secondly, the submerged arc deposit contained about 3 percent by weight of manganese whereas the open arc deposits averaged about 1 percent by weight of manganese.

It has now been discovered that by increasing slightly the manganese content of the flux-cored weld wire of the parent application, a weld wire can be produced which will deposit higher strength weld deposits when used in the open-arc welding method.

It is an object of the present invention to provide a novel flux-cored weld wire adapted to produce higher strength weld deposits.

Other objects and advantages will become apparent from the following description, treated as modifying the aforequoted sections from parent application Ser.

core composition, to provide atotal of up to 7.5 percent manganese in the weld rod. The carbon (graphite) in the core can be as low as 3 percent by weight of the core.

The following examples are given to demonstrate the effect of manganese levels on the strength of the 'weld deposit.

Cored wire welding electrodes were made from 7 parts by weight of nickel-iron alloy strip containing nominally about 55 percent nickel 0.35 percent manganese, 0.2 percent silicon, 0.05 percent carbon, 0.005 percent each of sulfur and phosphorous, 0.5 percent copper and about 44 percent iron bent to enclose about 3 parts by weight of the core compositions set forth in Table II.

TABLE 11 Percent by Weight Example No. l 2 3 4 5 Ingredients Nickel Magnesium Alloy 9 9 9 9 9 Graphite 6 6 6 6 6 Magnesium Oxide 2 2 2 2 2 Calcium-Silicon 4 4 4 4 4 Cryolite l l0 l0 l0 10 Ba F, 2 2 2 2 2 Nickel Powder 5 5 5 5 Electrolytic Manganese 8 l0 l2 l4 16 Ca F 54 52 50 48 46 TABLE III Weld Rod Mn in Core Tensile El Mn in Deposit Strength (k.5.i)

Commercial 6 64.1 1 l l 8 64.1 [0 2 10 23.5 2.30

3 12 7| .5 I65 2.83 4 l4 7 l .5 l9.0 3.22 5 16 73.5 l8.5 3.65 6 17 80.5 2| 7 24 79.7 I)

Table III shows that open-arc Weldments of excellent strength can be produced when the core composition contains about 15 to 30 percent manganese and more particularly about 15 percent about 20 percent by weight of manganese.

Although the present invention has been described in conjunction with preferred embodiments. it is to he understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and appended claims.

I claim:

1. In a welding electrode particularly adapted to be coil-fed to automatic welding machines and to weld cast iron at high rates using an open-arc comprising a tubular sheath of metal containing about 45 percent to 7 about 100 percent by weight of nickel with the balance,

if any, being essentially iron enclosing a core comprising a mixture of powders containing, in per cent by weight of core ingredients, about 0.7 percent to about 3.5 percent of metallic magnesium, about 5 percent to about 25 percent graphite and about 30 percent to about percent calcium fluoride, the balance of said core comprising slag forming and metallic ingredients said core being balanced with respect to said tubular sheath such that said tubular sheath comprises about 55 percent to about percent by weight of the total electrode, such that the total per cent of metallic nickel plus metallic iron in the total electrode is about 65 percent to about 80 percent and such that the ratio of nickel to metallic iron in the total electrode is at least about 0.67, the improvement comprising including in the core about 15 percent to about 30 percent by weight of manganese to provide up to about'7.5 percent by weight' of manganese in the total weld rod.

2. The weld rod of claim 1 containing in the core about 3 percent to about 5 percent graphite. 

1. IN A WELDING ELECTRODE PARTICULARLY ADAPTED TO BE COIL-FED TO AUTOMATIC WELDING MACHINES AND TO WELD CAST IRON AT HIGH RATES USING AN OPEN-ARC COMPRISING A TUBULAR SHEATH OF METAL CONTAINING ABOUT 45 PERCENT TO ABOUT 100 PERCENT BY WEIGHT OF NICKEL WITH THE BALANCE, IF ANY, BEING ESSENTIALLY IRON ENCLOS ING A CORE COMPRISING A MIXTURE OF POWDERS CONTAINING, IN PER CENT BY WEIGHT OF CORE INGREDIENTS, ABOUT 0.7 PERCENT TO ABOUT 3.5 PERCENT OF METALLIC MAGNESIUM, ABOUT 5 PERCENT TO ABOUT 25 PERCENT GRAPHITE AND ABOUT 30 PERCENT TO ABOUT 75 PERCENT CALCIUM FLUORIDE, THE BALANCE OF SAID CORE COMPRISING SLAG FORMING AND METALLIC INGREDIENTS SAID CORE BEING BALANCED WITH RESPECT TO SAID TUBULAR SHEATH SUCH THAT SAID TUBULAR SHEATH COMPRISES ABOUT 55 PERCENT TO ABOUT 80 PERCENT BY WEIGHT OF THE TOTAL ELECTRODE, SUCH THAT THE TOTAL PER CENT BY METALLIC NICKEL PLUS METALLIC IRON IN THE TOTAL ELECTRODE IS ABOUT 65 PERCENT TO ABOUT 80 PERCENT AND SUCH THAT THE RATIO OF NICKEL TO METALLIC IRON IN THE TOTAL ELECTRODE IS AT LEAST ABOUT 0.67, THE IMPROVEMENT COMPRISING INCLUDING IN THE CORE ABOUT 15 PERCENT TO ABOUT 30 PERCENT BY WEIGHT OF MANGANESE TO PROVIDE UP TO ABOUT 7.5 PERCENT BY WEIGHT OF MANGANESE IN THE TOTAL WELD ROD.
 2. The weld rod of claim 1 containing in the core about 3 percent to about 5 percent graphite. 